Copolymer membranes, fibers, products and methods

ABSTRACT

In accordance with at least selected embodiments, the present invention is directed to novel, improved, or modified porous membranes, fibers, porous fibers, products made from such membranes, fibers or porous fibers, and/or related methods of production, use, and/or the like. In accordance with at least certain embodiments, the present invention is directed to novel, improved, or modified microporous membranes or films, fibers, microporous fibers, materials or layers made from such membranes, fibers or porous fibers, and the like for use in textile materials, garments, products, and/or textile related applications. Microporous membranes, fibers, and/or microporous fibers are made of one or more copolymers, such as block or impact copolymers, or of at least one polyolefin combined with at least one copolymer as a means of improving the hand, drape, and/or surface coefficient of friction performance properties for use in textile garments, textile materials or textile related applications.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalApplication Ser. No. 61/723,058 filed Nov. 6, 2012 and of U.S.Provisional Application Ser. No. 61/892,730 filed Oct. 18, 2013, bothand each of which are incorporated by reference herein.

FIELD OF THE INVENTION

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, or modified porous membranes, fibers,porous fibers, products made from such membranes, fibers or porousfibers, and/or related methods of production, use, and/or the like. Inaccordance with at least certain embodiments, the present invention isdirected to novel, improved, or modified microporous membranes or films,fibers, microporous fibers, materials or layers made from suchmembranes, fibers or porous fibers, and the like for use in textilematerials, garments, products, and/or textile related applications. Inaccordance with at least certain selected embodiments, the presentinvention is directed to novel, improved, or modified microporousmembranes or films, fibers or microporous fibers, such as solid orhollow fibers, microporous hollow fibers, shaped fibers, materials,layers, or textiles made from such fibers or membranes, includingwovens, nonwovens, knits, bonded, flocked, and/or other textiles,laminates, composites, garments, and/or the like and which membranes,fibers, or porous fibers are preferably made of or comprised of one ormore copolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefin monomer types orwhich membranes, fibers, or porous fibers are preferably made of apolymer such as one or more polyolefins together with one or morecopolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefins. In accordance withat least particular embodiments, the present invention is directed tonovel, improved or modified microporous membranes or films, fibers ormicroporous fibers which are comprised of a polyolefin in combinationwith or blended with one or more block copolymers or impact copolymersas a means of improving the composition, characteristics, performance,and/or properties of the membranes, fibers, porous fibers, materials,layers or textiles made from such membranes, fibers or porous fibers,for example, improving the characteristics, performance, and/orproperties such as hand, drape, quietness, and/or surface coefficient offriction of the membranes, fibers, materials, layers or textiles such asmicroporous polyolefin membranes and/or polyolefin fibers in or fortextiles or textile end use applications. In accordance with at leastparticular selected embodiments, the present invention is directed tonovel, improved or modified polyolefin materials or compositions inwhich one or more polyolefins are combined or blended with one or moreblock or impact copolymers. In addition, in accordance with at leastparticular certain embodiments, the present invention is directed tonovel, improved or modified polyolefin materials or compositions inwhich one or more polyolefins are combined or blended with one or more,preferably one or more, block or impact copolymers, and where the blendor combination influences the performance properties of hand, drape,‘quietness’ with movement, and/or surface coefficient of friction ofmicroporous polyolefin membranes, materials, layers, and/or fibers madefrom such polyolefin materials or compositions and are used in or fortextile products and/or textile related end use applications.

BACKGROUND OF THE INVENTION

At least certain polyolefin (PO) microporous membranes and microporousfibers (or materials made therefrom) are known to be waterproof (or atleast water resistant) and air permeable due to their chemicalcomposition and structure. Examples of such polyolefin (PO) microporousmembranes and hollow fibers known to be waterproof (or water resistant)and air permeable are Celgard® Z-series membranes or Celgard® hollowfibers produced by Celgard, LLC of Charlotte, N.C.

Typically, polyolefin microporous membranes and fibers are thought to beundesirably stiff and plastic-like and as such may not be commonly usedin textile garments and/or related textile materials, laminates, orproducts or in other textile end uses or applications.

For at least certain conditions or applications, such as certain textilematerials or uses, a need exists for novel, improved or modifiedpolyolefin microporous membranes, polyolefin fibers, and/or polyolefinmicroporous fibers, and/or materials, layers, and/or textiles madetherefrom having novel, improved or modified compositions,characteristics, performance, and/or properties such as improved,modified, better, or good hand, soft drape, ‘quietness’ with movement,and/or lower surface coefficient of friction that may be desirable in atleast certain textiles, garments and/or related end use applications.

SUMMARY OF THE INVENTION

In accordance with at least selected embodiments, the present inventionmay address the above needs or issues and is directed to novel, improvedor modified microporous membranes, fibers and/or microporous fibers foruse in textiles, garments, textile garments, textile materials, ortextile related applications. In accordance with at least certainembodiments, the present invention is directed to novel, improved ormodified microporous membranes or films, fibers and/or microporousfibers which are comprised of one or more polyolefins (POs), one or morecopolymers such as block or impact copolymers preferably ofpolypropylene (PP) and polyethylene (PE), or one or more polyolefins(POs) mixed or blended with one or more copolymers such as block orimpact copolymers preferably of polypropylene (PP) and polyethylene(PE). In accordance with at least certain embodiments, the presentinvention is directed to novel, improved, and/or modified porousmembranes or films, fibers, and/or porous fibers made of or comprised ofa polyolefin and one or more block or impact copolymers whichpreferentially are made of polypropylene and polyethylene, or tomaterials, layers or textiles, laminates, composites, and/or the likemade from such membranes, films, fibers, or hollow fibers that arethemselves made of or comprised of a polyolefin and one or more block orimpact copolymers which preferentially are made of polypropylene andpolyethylene.

In another embodiment, the present invention is directed to novel,improved and/or modified membranes, films and/or fibers, such asmicroporous membranes, fibers and/or microporous fibers which arecomprised of a polyolefin in combination with one or more blockcopolymers such as impact copolymers where the polyolefins in thecopolymers include, but are not limited to, polypropylene, polyethylene,poly 1-butene, poly-4-methyl-1 pentene, polyhexene, polyoctene and/orblends, mixtures, or combinations thereof. When a polyolefin membrane orfiber is made of a polyolefin combined with one or more block or impactcopolymers, the modified membrane or fiber offers or provides formethods for designing modified microporous membranes, fibers ormicroporous fibers, or materials, layers, composites, laminates, ortextiles with targeted, enhanced performance properties in or fortextile related end use applications. Tailoring the choice ofcomposition, in the chemical structure of the polymeric blend orcomposition of the inventive modified composition, membrane or fiber, ormaterial, layer, composite, laminate, or textile made therewith ortherefrom can influence performance properties such as hand, drape,‘quietness’ with movement, and surface coefficient of friction therebyproducing microporous polyolefin membranes, fibers, microporous fibers,or materials, layers, composites, laminates, or textiles with betterhand, softer drape, quieter movement, and/or lower coefficient offriction resulting in, for example, a silkier touch.

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, or modified porous membranes, fibers,porous fibers, products made from such membranes, fibers or porousfibers, and/or related methods of production, use, and/or the like. Inaccordance with at least certain embodiments, the present invention isdirected to novel, improved, or modified microporous membranes or films,fibers, microporous fibers, materials or layers made from suchmembranes, fibers or porous fibers, and the like for use in textilematerials, garments, products, and/or textile related applications. Inaccordance with at least certain selected embodiments, the presentinvention is directed to novel, improved, or modified microporousmembranes or films, fibers or microporous fibers, such as solid orhollow fibers, microporous hollow fibers, shaped fibers, materials,layers, or textiles made from such fibers or membranes, includingwovens, nonwovens, knits, bonded, flocked, and/or other textiles,laminates, composites, garments, and/or the like and which membranes,fibers, or porous fibers are preferably made of or comprised of one ormore copolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefin monomer types orwhich membranes, fibers, or porous fibers are preferably made of apolymer such as one or more polyolefins together with one or morecopolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefins. In accordance withat least particular embodiments, the present invention is directed tonovel, improved or modified microporous membranes or films, fibers ormicroporous fibers which are comprised of a polyolefin in combinationwith or blended with one or more block copolymers or impact copolymersas a means of improving the composition, characteristics, performance,and/or properties of the membranes, fibers, porous fibers, materials,layers or textiles made from such membranes, fibers or porous fibers,for example, improving the characteristics, performance, and/orproperties such as hand, drape, quietness, and/or surface coefficient offriction of the membranes, fibers, materials, layers or textiles such asmicroporous polyolefin membranes and/or polyolefin fibers in or fortextiles or textile end use applications.

Conventional methods for altering the hand, drape and surfacecoefficient of friction of microporous polyolefin membranes typicallyinvolve coating applications which can be challenging to get to adhereand, in addition, can carry the risk that the coating may provefugitive. The inventive approach of using a block copolymer of two ormore polyolefins or using a combination or blend of polyolefin and oneor more block copolymers offers a method which is permanent and producesa range of differentiated textile materials having improved performanceproperties such as more desirable hand, drape and surface coefficient offriction for use in a variety of textile end use applications which mayalso require waterproof and breathability performance, such asouterwear, disposable garments, durable garments, textile materialsrequiring relative humidity equalization, and/or garments or items inmedical related applications.

Microporous polyolefin membranes or films can be manufactured by severalmethods including the dry stretch process (also known as the Celgard drystretch process) used by Celgard, LLC of Charlotte, N.C. and by the wetprocess method known as a phase separation or extraction process used byCelgard Korea Inc. of South Korea, Asahi of Japan and Tonen of Japan.Microporous membranes manufactured by these processes are often made ofthermoplastic polymers included, but not limited to, polyolefins such aspolypropylene, polyethylene, poly 1-butene, poly-4-methyl-1 penteneand/or blends, mixtures, or combinations thereof. The choice ofpolyolefin or polyolefins can affect the performance properties of themembranes for certain end use applications. The polyolefin (PO) can be ahomopolymer or a copolymer in composition. A homopolymer consists of onepolymer while a copolymer consists of two or more polymers arranged invarious sequence length distributions. For example, in the case of acopolymer, a monomer A can be copolymerized with a monomer B to formblock copolymer AA/BB/AA/BB which has blocks of repeat polymeric unitsAA and BB. This is only one example of numerous possible arrangements ofA and B polymeric units which can make up a block copolymer (BCP) or animpact copolymer (ICP). In addition, in accordance with the presentinvention, the composition, length, amount, order, and arrangement ofthe block copolymer segments AA/BB or AAAA/BBBB, for example, caninfluence the performance properties of hand, drape, ‘quietness’ withmovement, and surface coefficient of friction in microporous PO/ICP,PO/BCP, ICP or BCP membranes and fibers in textile end use applications.The term ‘block copolymer’ is one type of copolymer or impact copolymer,with other commonly known copolymers being random and graftedcopolymers.

The present methods of modification may be preferred to be costeffective and easy to control in order to facilitate custom tailoring ofperformance properties such as hand, soft drape, ‘quietness’ withmovement, and lower surface coefficient of friction for use in at leastcertain textile garments and textile related end use application.

In accordance with at least selected embodiments, the inventivemicroporous membrane can be manufactured by the dry stretch processwhere a polyolefin resin is extruded by blown film technique or bycasted film method to form a nonporous precursor film which is then coldand hot stretched in the machine direction (uniaxially) to form amicroporous membrane with a final thickness typically less than 75 μm,preferably from about 12-25 μm (but may be thinner or thicker dependingon the end use). In accordance with at least certain embodiments of thecurrent inventive membrane, the polyolefin resin can be one or moreblock copolymers (BCPs) or impact copolymers (ICPs) which are preferablyeach made of polypropylene and polyethylene. Alternatively, thepolyolefin resin can be extruded by blown film technique or by castedfilm method to form a nonporous precursor film which is then cold and/orhot stretched in both the machine and transverse directions (biaxially)to form a microporous membrane with a final thickness typically lessthan 75 μm, preferably from about 12-25 μm.

In accordance with a further embodiment, one or more impact copolymersconsisting preferentially of polypropylene and polyethylene can beextruded by a blown film technique or by a casted film method to form anonporous precursor film which is then cold and hot stretched initiallyin the machine direction (MD) and sequentially stretched in thetransverse direction (TD) to form a biaxially stretched or biaxiallyoriented (BO) microporous membrane according to the method described inpublished US 2011/0223486 (herein incorporated by reference) where thebiaxial stretch step includes simultaneous machine direction relax.

In accordance with a further embodiment, one or more impact copolymersconsisting preferentially of polypropylene and polyethylene, can beextruded by a blown film technique or by a cast or casted film method toform a nonporous precursor film which is then cold and hot stretchedinitially in the machine direction and sequentially stretched in thetransverse direction to form a biaxially stretched or biaxially oriented(BO) microporous membrane according to the method described inUS2011/0223486 where the biaxial stretch step does not includesimultaneous machine direction relax.

In accordance with a certain further embodiment, a primarilypolypropylene (PP) based block copolymer (BCP) with 90-97% polypropylenecontent, can be compounded with a beta-nucleating (BN) agent andextruded, using a cast method, to form a nonporous beta-nucleatedpolypropylene based BCP precursor film. Biaxial stretching of the betanucleated polypropylene precursor casted film fractures the interfaceswhich exist between regions of beta nucleated PP and regions of alphanucleated of PP. The fracturing process forms pores in thebeta-nucleated biaxially oriented polypropylene (BN-BOPP) membraneproducing a microporous membrane with a thickness of less than 75 μm,preferably from about 12-25 μm.

In a further embodiment of the current inventive membrane comprised of apolyolefin (PO) in combination with one or more block or impactcopolymers (BCPs or ICPs), a polyolefin combined with one or more impactor block copolymers is extruded by a blown film technique or by a castedfilm method to form a nonporous precursor film which is then cold andhot stretched in the machine direction (uniaxially) to form amicroporous membrane or film.

In accordance with a further embodiment, a polyolefin (PO) incombination with one or more impact copolymers (ICP) can be extruded bya blown film technique or by a casted film method to form a nonporousprecursor film which is then cold and hot stretched in the machinedirection (MD) and sequentially stretched in the transverse direction(TD) to form a biaxially stretched or biaxially oriented (BO)microporous membrane according to the stretch method described in US2011/0223486. The transverse stretching step includes a simultaneousmachine direction relax step to produce a biaxially oriented (BO)microporous membrane.

In accordance with a further embodiment, a polyolefin (PO) incombination with one or more impact copolymers (ICP) can be extruded bya blown film technique or by a casted film method to form a nonporousprecursor film which is then cold and hot stretched in the machinedirection and sequentially stretched in the transverse direction to forma biaxially stretched or biaxially oriented (BO) microporous membraneaccording to the method described in US 2011/0223486. The transversestretching step does not include a simultaneous machine direction relaxstep to produce a biaxially oriented (BO) microporous membrane.

In accordance with certain further embodiments, a polyolefin (PO) incombination with one or more impact copolymers (ICP), where the ICP isprimarily a polypropylene (PP) based ICP copolymer with a 90-97% PPcontent, can be compounded with a beta-nucleating (BN) agent andextruded using a cast method to form a nonporous beta nucleated PO/ICPprecursor. Biaxial stretching of the beta nucleated polypropyleneprecursor casted film fractures the interfaces which exist betweenregions of beta nucleated PP and regions of alpha nucleated PP. Thefracturing process forms pores in the beta-nucleated biaxially orientedpolypropylene (BN-BOPP) membrane producing a microporous membrane with athickness of less than 75 μm, preferably from about 12-25 μm.

In accordance with at selected embodiments, the present invention isdirected to novel, modified microporous membranes, films, fibers, orhollow fibers (or materials, layers, textiles, composites or laminatesmade therefrom) comprised of either 1) one or more block or impactcopolymers (BCPs or ICPs) or 2) a polyolefin in combination with one ormore BCPs or ICPs. The option of using one or more block or impactcopolymers or of using a polyolefin in combination with one or moreblock or impact copolymers provides a method to produce a range ofdifferentiated textile materials having improved performance propertiessuch as more desirable hand, drape and surface coefficient of frictionfor use in a variety of textile end use applications which may alsorequire waterproof and breathability performance, such as outerwear,disposable garments, durable garments, textile materials requiringrelative humidity equalization and garments or items in medical relatedapplications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of examples of block copolymers orimpact copolymers made up of blocks of different polymerized monomers.Preferably, the block or impact copolymers (BCPs or ICPs) are made oftwo or more monomer types, such as, propylene and ethylene monomers.

FIG. 2 is a respective surface SEM images of the product of Example 5 atdifferent magnifications.

FIG. 3 is a respective surface SEM images of the product of Example 5 atdifferent magnifications.

FIG. 4 is a respective surface SEM images of the product of Example 5 atdifferent magnifications.

FIG. 5 is a respective surface SEM images of the product of Example 5 atdifferent magnifications.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, or modified porous membranes, fibers,porous fibers, products made from such membranes or fibers, and/orrelated methods of production, use, and/or the like. In accordance withat least certain embodiments, the present invention is directed tonovel, improved, or modified microporous membranes or films, fibers,microporous fibers, hollow fibers, materials or layers made from suchmembranes or fibers, and the like for use in textile materials,garments, products, and/or textile related applications. In accordancewith at least certain selected embodiments, the present invention isdirected to novel, improved, or modified microporous membranes, fibersor microporous fibers, such as solid or hollow fibers, microporoushollow fibers, shaped fibers, materials, layers, or textiles made fromsuch fibers or membranes, and/or the like and which membranes, fibers,films, or hollow fibers are preferably made of or comprised of one ormore copolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefins or which membranes,fibers, films, or hollow fibers are preferably made of a polymer such asone or more polyolefins together with one or more copolymers such asblock copolymers or impact copolymers preferably comprising orconsisting of two or more polyolefins. In accordance with at leastparticular embodiments, the present invention is directed to novel,improved or modified microporous membranes, fibers or microporous fiberswhich are comprised of a polyolefin in combination with or blended withone or more block copolymers or impact copolymers as a means ofimproving the composition, characteristics, performance, and/orproperties of the membranes, fibers, materials, layers or textiles madefrom such membranes or fibers, for example, improving thecharacteristics, performance, and/or properties such as hand, drape,quietness, and/or surface coefficient of friction of the membranes,fibers, materials, layers or textiles such as microporous polyolefinmembranes and/or polyolefin fibers in or for textiles or textile end useapplications. In accordance with at least particular selectedembodiments, the present invention is directed to novel, improved ormodified polyolefin materials or compositions in which one or morepolyolefins are combined or blended with one or more block or impactcopolymers. In addition, in accordance with at least particular certainembodiments, the present invention is directed to novel, improved ormodified polyolefin materials or compositions in which one or morepolyolefins are combined or blended with one or more block or impactcopolymers, and where the blend or combination influences theperformance properties of hand, drape, ‘quietness’ with movement, and/orsurface coefficient of friction of microporous polyolefin membranes,materials, layers, and/or fibers made from such polyolefin materials orcompositions and are used in or for textile products and/or textilerelated end use applications.

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, or modified, microporous membranes,fibers or microporous fibers (or layers, materials, composites,laminates, or textiles made therefrom) for use in textile garments,textile materials or textile related applications. In accordance with atleast certain embodiments, the present invention is directed to novel,improved or modified microporous membranes, fibers, porous fibers, orhollow fibers which are comprised of a polyolefin made or consisting ofone or more impact or block copolymers (abbreviated here as BCPs orICPs), preferably polypropylene and polyethylene or of a polyolefinblended or mixed with one or more impact or block copolymers. FIG. 1 isa schematic representation of possible copolymer block repeat unitsconsisting of a monomer A (represented as “A” in FIG. 1) and monomer B(represented as “B” in FIG. 1) preferably propylene and ethylenemonomers.

In accordance with at least certain embodiments, the current inventionis directed to novel, improved or modified microporous membranes,fibers, porous fibers, or hollow fibers comprised of one or more blockcopolymers (BCPs) which preferentially are made of polypropylene andpolyethylene present at mole fractions between 1% and 50%, and morepreferentially made of polypropylene and polyethylene present at molefractions between 3% and 10%. The novel, improved, or modifiedmicroporous membranes, fibers, porous fibers, hollow fibers, ormicroporous fibers for use in materials, layers, composites, textiles,and/or the like for textile products or other end use applicationsand/or the like, and may include block or impact copolymer of two ormore polyolefins as a means to improve the characteristics orperformance properties of hand, drape, quietness, surface coefficient offriction, and/or the like. The block or impact copolymer may be presentat a mole fraction between 1% and 50%. The microporous membranes,fibers, porous fibers, hollow fibers, or microporous fibers may becomprised of a polyolefin combined with a block or impact copolymercomprised of two or more polyolefins, preferably polypropylene andpolyethylene, present at mole fractions between 1% and 50%, and morepreferentially of polypropylene and polyethylene present at molefractions between 3% and 10%.

In another embodiment, the present invention is directed to novel,improved or modified microporous membranes or films, fibers, porousfibers, or hollow fibers which are comprised of a polyolefin (PO) incombination with one or more impact copolymers (ICPs). The one or moreimpact copolymers preferably consist of polyolefins which include butare not limited to, polypropylene, polyethylene, poly 1-butene,poly-4-methyl-1 pentene, polyhexene, polyoctene and/or blends, mixtures,or combinations thereof. When a polyolefin is combined with one or moreimpact copolymers, the length, amount, arrangement and order of PO/ICPpolymers or segments in the inventive modified microporous membraneoffers methods for designing modified microporous membranes, films,fibers, or porous fibers with targeted, enhanced performance propertiesin or for textile related end use applications. The mole fractioncomposition of polypropylene and polyethylene present in the ICP or BCPsegments or in the PO/ICP or PO/BCP polymeric microporous membranes canbe varied and is preferably between 1% and 50%, and more preferablybetween 3% and 10%. Tailoring the choice of composition, length, order,amount, and arrangement of BCP or ICP segments in the polymeric backboneor PO/ICP or PO/BCP polymers in the chemical structure of the polymerblend or mixture or composition of the inventive modified microporousmembrane can influence membrane or product performance properties suchas hand, drape, ‘quietness’ with movement, and surface coefficient offriction producing microporous polyolefin membranes with softer drape,quieter movement and lower coefficient of friction, for example,resulting in a silkier touch.

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, or modified porous membranes, fibers,porous fibers, products made from such membranes, fibers or porousfibers, and/or related methods of production, use, and/or the like. Inaccordance with at least certain embodiments, the present invention isdirected to novel, improved, or modified microporous membranes or films,fibers, microporous fibers, materials or layers made from suchmembranes, fibers or porous fibers, and the like for use in textilematerials, garments, products, and/or textile related applications. Inaccordance with at least certain selected embodiments, the presentinvention is directed to novel, improved, or modified microporousmembranes or films, fibers or microporous fibers, such as solid orhollow fibers, microporous hollow fibers, shaped fibers, materials,layers, or textiles made from such fibers or membranes, includingwovens, nonwovens, knits, bonded, flocked, and/or other textiles,laminates, composites, garments, and/or the like and which membranes,fibers, or porous fibers are preferably made of or comprised of one ormore copolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefin monomer types orwhich membranes, fibers, or porous fibers are preferably made of apolymer such as one or more polyolefins together with one or morecopolymers such as block copolymers or impact copolymers preferablycomprising or consisting of two or more polyolefins. In accordance withat least particular embodiments, the present invention is directed tonovel, improved or modified microporous membranes or films, fibers ormicroporous fibers which are comprised of a polyolefin in combinationwith or blended with one or more block copolymers or impact copolymersas a means of improving the composition, characteristics, performance,and/or properties of the membranes, fibers, porous fibers, materials,layers or textiles made from such membranes, fibers or porous fibers,for example, improving the characteristics, performance, and/orproperties such as hand, drape, quietness, and/or surface coefficient offriction of the membranes, fibers, materials, layers or textiles such asmicroporous polyolefin membranes and/or polyolefin fibers in or fortextiles or textile end use applications.

Microporous polyolefin membranes can be manufactured by several methodsand may be made of thermoplastic polymers including, but not limited to,polyolefins such as polypropylene, polyethylene, poly 1-butene,poly-4-methyl-1 pentene and/or blends, mixtures, or combinationsthereof. The choice of polyolefin(s) can affect the performanceproperties of the membranes in certain end use applications. Thepolyolefin (PO) can be a homopolymer or a copolymer in composition. Thecomposition, length, order, amount, and arrangement of copolymer orimpact or block copolymers can influence the performance properties ofhand, drape, ‘quietness’ with movement, and surface coefficient offriction in microporous polyolefin membranes and/or fibers for or intextile products or end use applications. In the inventive membrane orfiber, the mole fraction composition of polypropylene and polyethylenepresent in the BCP or ICP or in the ICP or BCP portion of the PO/ICP orPO/BCP polymeric microporous membrane can be varied and is preferablybetween 1% and 50%, and more preferably between 3% and 10%.

In accordance with at least selected embodiments, the inventivemicroporous membrane can be manufactured by the dry stretch processwhere the polyolefin resin is extruded using a blown film technique orusing a casted film method to form a nonporous precursor film which isthen cold and/or hot stretched in the machine direction (uniaxially) toform a microporous membrane with a final thickness typically less than75 μm, preferably from about 12-25 μm. In accordance with at leastcertain embodiments of the current inventive membrane, the polyolefinresin can be an impact copolymer (ICP) or block copolymer (BCP) which ispreferably made of polypropylene and polyethylene. The ICP or BCP can beextruded by blown film technique or by casted film method to form anonporous precursor film which is then cold and hot stretched in themachine direction (uniaxially) to form a microporous membrane with afinal thickness typically less than 75 μm, preferably from about 12-25μm.

In accordance with a further embodiment, one or more impact copolymersICPs consisting preferentially of polypropylene and polyethylene at amole fraction content preferably between 1% and 50%, and more preferablybetween 3% and 10%, are extruded using a blown film technique or using acasted film method to form a nonporous precursor film which is then coldand hot stretched initially in the machine direction and sequentiallystretched in the transverse (TD) direction to form a biaxially stretchedor biaxially oriented (BO) microporous membrane according to the methoddescribed in US2011/0223486. The transverse stretching step includes asimultaneous machine direction relax step and produces a biaxiallyoriented (BO) microporous membrane with a final thickness typically lessthan 75 μm, preferably from 10-40 μm, more preferably 15-30 μm, and mostpreferably about 8-20 μm.

In accordance with a further embodiment, one or more impact copolymers(ICP) which consist preferentially of polypropylene and polyethylene ata mole fraction content preferably between 1% and 50%, and morepreferably between 3% and 10%, are extruded using a blown film techniqueor using a casted film method to form a nonporous precursor film whichis then cold and hot stretched initially in the machine direction andsequentially stretched in the transverse (TD) direction to form abiaxially stretched or biaxially oriented (BO) microporous membraneaccording to the method described in US2011/0223486. The transversestretching step does not include a simultaneous machine direction relaxstep and produces a biaxially oriented (BO) microporous membrane with afinal thickness typically less than 75 μm, preferably from 10-40 μm,more preferably 15-30 μm, and most preferably 8-20 μm.

In accordance with a certain further embodiment, a primarilypolypropylene based impact copolymer (ICP) with 90-97% polypropylenecontent, can be compounded with a beta-nucleating (BN) agent andextruded using a cast method to form a nonporous beta-nucleatedpolypropylene based ICP precursor film which is less than 300 μm,preferably less than 150 μm, in thickness. Polypropylene is apolymorphic semi-crystalline polymer which can crystallize in alpha andbeta crystalline forms which have different densities.

Beta nucleating agents convert polypropylene from the more common alpha(α) crystal state to the less common beta (β) crystal state whenpolypropylene is extruded and cast onto a roll which is maintained at acontrolled temperature specifically selected to optimize beta crystalgrowth. Biaxial stretching of the beta nucleated polypropylene based ICPprecursor film fractures the interfaces which exist between regions ofbeta nucleated PP and α nucleated PP. The fracturing process at theinterfaces between the β nucleated PP and α nucleated PP regions formsmicropores and the result is a beta-nucleated biaxially orientedpolypropylene (BN-BOPP) membrane with a thickness of less than 75 μm,preferably from 12-25 μm.

A further embodiment of the current inventive membrane comprised of apolyolefin (PO) in combination with one or more impact copolymers (ICP)is extruded using a blown film technique or using a casted film methodto form a nonporous precursor film which is then cold and hot stretchedin the machine direction (uniaxially) to form a microporous membranewith a final thickness typically less than 75 μm, preferably from about12-25 μm.

In accordance with a further embodiment of the current inventivemembrane comprised of a polyolefin (PO) in combination with one or moreimpact copolymers (ICP) is extruded using a blown film technique orusing a casted film method to form a nonporous precursor film which isthen cold and hot stretched the machine direction and sequentiallystretched in the transverse (TD) direction to form a biaxially stretchedor biaxially oriented (BO) microporous membrane according to the methoddescribed in US 2011/0223486. The transverse stretching step includes asimultaneous machine direction relax step which produces a biaxiallyoriented (BO) microporous membrane with a final thickness typically lessthan 75 μm, preferably from 10-40 μm, more preferably 15-30 μm, and mostpreferably 8-20 μm.

In accordance with a further embodiment of the current inventivemembrane comprised of a polyolefin (PO) in combination with one or moreimpact copolymers (ICP) is extruded using a blown film technique orusing a casted film method to form a nonporous precursor film which isthen cold and hot stretched the machine direction and sequentiallystretched in the transverse direction to form a biaxially stretched orbiaxially oriented (BO) microporous membrane according to the methoddescribed in US 2011/0223486. The transverse stretching step does notinclude a simultaneous machine direction relax step which produces abiaxially oriented (BO) microporous membrane with a final thicknesstypically less than 75 μm, preferably from 10-40 μm, more preferably15-30 μm, and most preferably 8-20 μm.

In accordance with a certain further embodiments, a polyolefin (PO) incombination with one or more impact copolymers (ICP)(or BCP), where theICP is primarily a polypropylene based ICP copolymer with a 90-97% PPcontent, can be compounded with a beta-nucleating (BN) agent andextruded using a cast method to form a nonporous beta nucleated PO/BCPprecursor film which is less than 300 μm in thickness. Polypropylene isa polymorphic semi-crystalline polymer which can crystallize in alphaand beta crystalline forms which have different densities. Betanucleating agents convert polypropylene from the more common alpha (α)crystal state to the less common beta (β) crystal state whenpolypropylene is extruded and cast onto a roll which is maintained at acontrolled temperature specifically selected to optimize beta crystalgrowth. Biaxial stretching of the beta nucleated polypropylene based ICPprecursor film fractures the interfaces which exist between regions ofbeta nucleated PP and α nucleated PP. The fracturing process at theinterfaces between the β nucleated PP and α nucleated PP regions formsmicropores and the result is a beta-nucleated biaxially orientedpolypropylene (BN-BOPP) membrane with a thickness of less than 75 μm,preferably from 12-25 μm.

In accordance with at selected embodiments, the present invention isdirected to novel, modified microporous membranes, fibers, porousfibers, or microporous hollow fibers comprised of either 1) an impactcopolymer (ICP)(or BCP) consisting of two or more polyolefins or 2) apolyolefin in combination with an impact copolymer (ICP)(or BCP)consisting of two or more polyolefins. The option of using an impactcopolymer (ICP) or of using a polyolefin in combination with one or moreimpact copolymers (ICP) provides a method to produce a range ofdifferentiated textile materials having improved performance propertiessuch as more desirable hand, drape and surface coefficient of frictionfor use in a variety of textile end use applications which also requirewaterproof and breathability performance, such as outerwear, disposablegarments, durable garments, textile materials requiring relativehumidity equalization and garments/items in medical relatedapplications.

Many other modifications and variations of the present invention arepossible to the skilled practitioner in the field in light of theteachings herein. It is therefore understood that, within the scope ofthe claims, the present invention can be practiced other than as hereinspecifically described.

EXAMPLES Example 1

An impact copolymer polyolefin resin is melt extruded to from anonporous precursor membrane 25 μm in thickness. The nonporous precursormembrane is then stretched uniaxially in the machine direction (MD) toproduce a microporous film which is 20.8 μm in thickness and has a JISGurley value=1354 seconds. Table 1 lists the properties of the inventivemicroporous film in Example 1.

TABLE 1 Physical Properties of Example 1. Property Value Thickness, μm20.8 JIS Gurley, s 1354 Basis weight, g/m² 10.4 % MD shrinkage 90° C./1hour 12.1 MD tensile stress, kgf/cm² 1538 TD tensile stress, kgf/cm²163.8 % MD elongation, 52.4 % TD elongation, 651.9

Example 2

According to the same manner as that described in Example 1, theuniaxially stretched microporous membrane produced in Example 1 wasbiaxially stretched in transverse direction (TD) stretching devicewithout machine direction (MD) relax. The TD stretched membrane wasstretched in the TD direction 2 to 4 times its input width. Theresulting microporous membrane had a JIS gurley<100 which is acceptablelevel of air permeability to function as a breathable textile membrane.

Example 3

According to the same manner as that described in Example 1, theuniaxially stretched microporous membrane produced in Example 1 wasbiaxially stretched in transverse direction (TD) stretching as describedin US 2011/0223486 with a simultaneous Machine direction relax step. TDstretching at 4.5× stretch and a 0-16% overall MD relax produced amicroporous membrane with a thickness of 10.9 μm and a JIS gurleyvalues=73 seconds. Table 2 lists the physical properties of theinventive microporous film in Example 3.

TABLE 2 Physical Properties of Example 3. Property Value Thickness, μm10.9 JIS Gurley, s 73 Basis weight, g/m² 2.6 % MD shrinkage 90° C./1hour 6.6 % TD shrinkage 90° C./1 hour 0.87 Puncture strength, g 69.9 MDtensile stress, kgf/cm² 397.6 TD tensile stress, kgf/cm² 393.3 % MDelongation 67.9 % TD elongation 43.1

Example 4

An impact copolymer polyolefin resin is melt extruded to form anonporous precursor membrane 35 μm in thickness. The nonporous precursormembrane is then stretched uniaxially in the machine direction (MD) toproduce a microporous film which is 26 μm in thickness and has a JISGurley value=3,454 seconds. Table 3 lists the properties of theinventive microporous film in Example 4.

TABLE 3 Physical Properties of Example 4. Property Value Thickness, μm26 JIS Gurley, s 3454 Basis weight, g/m² 15.5 % MD shrinkage 90° C./10.6 hour MD tensile stress, 1612 kgf/cm² TD tensile stress, 194 kgf/cm²% MD elongation, 78.2 % TD elongation, 685.8

Example 5

According to the same manner as that described in Example 4, auniaxially stretched microporous membrane 26 μm thick, producedsimilarly to Example 3 was biaxially stretched in transverse direction(TD) stretching as described in US 2011/0223486 with a simultaneousmachine direction relax step. TD stretching at 4.5× stretch and a 0-16%overall MD relax produced a microporous membrane with a thickness of 19μm and a JIS gurley values=25 seconds.

TABLE 4 Physical Properties of Example 5. Property Value Thickness, μm19 JIS Gurley, s 25 Basis weight, g/m² 4.0 % MD shrinkage 90° C./1 hour5.7 % TD shrinkage 90° C./1 hour 4.2 Puncture strength, g 124 MD tensilestress, kgf/cm² 561.0 TD tensile stress, kgf/cm² 266.3 % MD elongation120.5 % TD elongation 58.8

Test Methods

Gurley is defined as the Japanese Industrial Standard (JIS Gurley) andis measured using the OHKEN permeability tester. JIS Gurley is definedas the time in seconds required for 100 cc of air to pass through onesquare inch of film at a constant pressure of 4.9 inches of water.

Thickness is measured in micrometers, μm, using the Emveco Microgage210-A micrometer thickness tester and test procedure ASTM D374.

Machine Direction (MD) and Transverse Direction (TD) tensile strengthare measured using Instron Model 4201 according to ASTM-882 procedure.

% MD elongation at break is the percentage of extension of a test samplealong the machine direction of the test sample measured at the maximumtensile strength needed to break a sample.

% TD elongation at break is the percentage of extension of a test samplealong the transverse direction of the test sample measured at themaximum tensile strength needed to break a sample.

Puncture Strength is measured using Instron Model 4442 based on ASTMD3763. The measurements are made across the width of the microporousmembrane and the puncture strength defined as the force required topuncture the test sample.

Basis Weight the weight per unit sample area of a material and can beexpressed in grams/meter squared. It is the weight in grams of a testsample of known area in meters squared.

% Shrinkage is measured by placing a sample in an oven at 90 deg C. for1 hour. Shrinkage has been measured in both Machine Direction (MD) andTransverse Direction (TD).

When a polyolefin is combined with one or more impact or blockcopolymers, the length, amount, arrangement, and order of polyolefin andimpact copolymers in the chemical structure of the polymer makeup of theinventive modified microporous membrane offers methods for designingmodified microporous membranes or films, fibers, porous fibers, orhollow fibers with targeted, enhanced performance properties in textilerelated end use applications.

Certain microporous polyolefin membranes are highly hydrophobic andexceptionally breathable, which makes them ideal as the barrier layer inwaterproof/breathable textiles such as high-performance outerwear.Traditionally, in the development of such polyolefin films, raw materialpolymers have been selected, among other factors, with a view towardproviding physically robust films. This has resulted in stiffer filmsthat tend to crinkle, thus providing less than ideal “hand” (i.e.tactile experience). In accordance with the present invention, onemethod for improving the hand of such PO films is to use apolypropylene/polyethylene block copolymer resin.

PP/PE block copolymers are available from various resin manufacturers.By using a block copolymer that includes at least a small percentage ofPE (preferably less than 5%), the resulting film is less stiff, thusgiving a softer drape and quieter movement, and also has a lowercoefficient of friction, thus giving a silkier touch. Also, such blockcopolymer films appear to be suitable for TD stretching and 60 inch wide(or wider) porous films for textile applications can be made.

In accordance with one example, a microcreped microporous polymermembrane, such as a polyolefin microporous membrane is laminated to aporous polymer non-woven material or mesh, such as a polyolefinnon-woven mesh, then microcreped.

In accordance with certain other non-limiting examples, here is a listof selected possible products, laminates, combinations, embodiments, orexamples using the inventive porous membrane or fiber layer:

-   -   1.) Inventive porous membrane or fiber layer+PE or PP non-woven    -   2.) Face fabric+Inventive porous membrane or fiber layer+PE or        PP non-woven inner layer    -   3.) PE or PP non-woven+Inventive porous membrane or fiber        layer+PE or PP non-woven    -   4.) Face fabric+Inventive porous membrane or fiber layer+Fabric        inner layer    -   5.) Face fabric+two layers of Inventive porous membrane or fiber        layer+Fabric inner layer    -   6.) Face fabric+PP non-woven+Inventive porous membrane or fiber        layer+Fabric inner layer    -   7.) Face fabric+Inventive porous membrane or fiber layer    -   8.) Inventive porous membrane or fiber layer+Adhesive+PE or PP        non-woven    -   9.) Face fabric+Adhesive+Inventive porous membrane or fiber        layer+PE or PP non-woven inner layer    -   10.) Face fabric+Adhesive+Inventive porous membrane or fiber        layer+Adhesive+PE or PP non-woven inner layer    -   11.) Face fabric+Inventive porous membrane or fiber        layer+Adhesive+PE or PP non-woven inner layer    -   12.) PE or PP non-woven+Adhesive+Inventive porous membrane or        fiber layer+PE or PP non-woven    -   13.) PE or PP non-woven+Adhesive+Inventive porous membrane or        fiber layer+Adhesive+PE or PP non-woven    -   14.) PE or PP non-woven+Inventive porous membrane or fiber        layer+Adhesive+PE or PP non-woven    -   15.) Face fabric+Adhesive+Inventive porous membrane or fiber        layer+Fabric inner layer    -   16.) Face fabric+Inventive porous membrane or fiber        layer+Adhesive+Fabric inner layer    -   17.) Face fabric+Adhesive+Inventive porous membrane or fiber        layer+Adhesive+Fabric inner layer    -   18.) Face fabric+two layers of Inventive porous membrane or        fiber layer    -   19.) Face fabric+Adhesive+two layers of Inventive porous        membrane or fiber layer    -   20.) Face fabric+Adhesive+two layers of Inventive porous        membrane or fiber layer+Fabric inner layer    -   21.) Face fabric+two layers of Inventive porous membrane or        fiber layer+Adhesive+Fabric inner layer    -   22.) Face fabric+Adhesive+two layers of Inventive porous        membrane or fiber layer+Adhesive+Fabric inner layer    -   23.) Face fabric+Adhesive+Inventive porous membrane or fiber        layer+Adhesive+Inventive porous membrane or fiber        layer+Adhesive+Fabric inner layer    -   24.) Face fabric+Adhesive+PP non-woven+Inventive porous membrane        or fiber layer    -   25.) Face fabric+Adhesive+PP non-woven+Adhesive+Inventive porous        membrane or fiber layer    -   26.) Face fabric+PP non-woven+Adhesive+Inventive porous membrane        or fiber layer    -   27.) Face fabric+Adhesive+PP non-woven+Inventive porous membrane        or fiber layer+Fabric inner layer    -   28.) Face fabric+PP non-woven+Inventive porous membrane or fiber        layer+Adhesive+Fabric inner layer    -   29.) Face fabric+Adhesive+PP non-woven+Inventive porous membrane        or fiber layer+Adhesive+Fabric inner layer    -   30.) Face fabric+Adhesive+PP non-woven+Adhesive+Inventive porous        membrane or fiber layer+Adhesive+Fabric inner layer    -   31.) Face fabric+Adhesive+Inventive porous membrane or fiber        layer

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, or modified porous membranes, fibers,products, and/or related methods. In accordance with at least certainembodiments, the present invention is directed to novel, improved ormodified microporous membranes, fibers, and the like for use in textilematerials, garments, products, and/or textile related applications. Inaccordance with at least certain selected embodiments, the presentinvention is directed to novel, improved, or modified microporousmembranes, fibers, porous fibers, or microporous hollow fibers which aremade of or comprised of a copolymer such as an impact copolymercomprising or consisting of two or more polyolefins. In accordance withat least particular embodiments, the present invention is directed tonovel, improved or modified microporous membranes, fibers, porous fibersor hollow fibers which are comprised of a polyolefin in combination withone or more impact copolymers as a means of improving the composition,characteristics, performance and/or properties of the material ortextile such as hand, drape and surface coefficient of friction of themicroporous polyolefin membranes and/or fibers in or for textile end useapplications. In addition, a polyolefin can be combined or blended withone or more impact copolymers, where the length, amount, arrangement andorder of the polyolefin and/or impact copolymers in the chemicalstructure of the polymer mix of the inventive modified microporousmembranes and fibers influences the performance properties of hand,drape, ‘quietness’ with movement, and/or surface coefficient of frictionof the microporous polyolefin membranes and/or fibers-in or for textileproducts and/or end use applications.

The preferred inventive laminated or composite microporous membrane maybe further improved, treated or modified using a technique or treatmentsuch as a coating or microcreping to introduce permanent small,regularly spaced, crepes, profiles, compactions, pleats, or wrinklesinto the laminated or composite microporous membrane for the purpose ofimproving mechanical strength, elasticity and/or resiliency. Inaddition, the inventive microcreped microporous laminated membrane mayhave improved ‘hand’ or softness, improved ‘next-to-the-skin’ softness,and/or is quiet without crinkling noises during movement, which may bedesired performance properties or characteristics of or in textilegarments, materials or applications.

In accordance with at least selected embodiments, objects or aspects ofthe present invention, there are provided novel, improved, or modifiedporous membranes, fibers, products, and/or related methods, novel,improved, or modified microporous membranes, fibers, and the like foruse in textile materials, garments, products, and/or textile relatedapplications, novel, improved, or modified microporous membranes orfilms, fibers, porous fibers, or hollow fibers which are made of orcomprised of a copolymer such as an impact copolymer comprising orconsisting of two or more polyolefins, novel, improved or modifiedmicroporous membranes or films, fibers, porous fibers, or hollow fibers(or articles, layers, composites, laminates, materials, textiles, or thelike made therefrom) which are comprised of a polyolefin in combinationwith one or more impact copolymers as a means of improving thecomposition, characteristics, performance and/or properties of thematerial or textile such as hand, drape and surface coefficient offriction of the microporous polyolefin membranes and/or fibers in or fortextile end use applications, a polyolefin can be combined or blendedwith one or more impact copolymers, where the blend or combinationinfluences the performance properties of hand, drape, ‘quietness’ withmovement, and/or surface coefficient of friction of the microporouspolyolefin membranes and/or fibers in or for textile products and/or enduse applications, and/or the like.

In at least one embodiment, microporous membranes, fibers, and/ormicroporous fibers are made of one or more copolymers, such as block orimpact copolymers, or of at least one polyolefin combined with at leastone copolymer as a means of improving the hand, drape, and/or surfacecoefficient of friction performance properties for use in textilegarments, textile materials or textile related applications.

In accordance with at least selected embodiments, objects or aspects,the present invention is directed to novel, improved, or modified porousmembranes, fibers, porous fibers, products made from such membranes,fibers or porous fibers, and/or related methods of production, use,and/or the like, microporous membranes or films, fibers, microporousfibers, materials or layers made from such membranes, fibers or porousfibers, and the like for use in textile materials, garments, products,and/or textile related applications, microporous membranes or films,fibers or microporous fibers, such as solid or hollow fibers,microporous hollow fibers, shaped fibers, materials, layers, or textilesmade from such fibers or membranes, including wovens, nonwovens, knits,bonded, flocked, and/or other textiles, laminates, composites, garments,and/or the like and which membranes, fibers, or porous fibers preferablymade of or comprised of one or more copolymers such as block copolymersor impact copolymers preferably comprising or consisting of two or morepolyolefin monomer types or which membranes, fibers, or porous fibersare preferably made of a polymer such as one or more polyolefinstogether with one or more copolymers such as block copolymers or impactcopolymers preferably comprising or consisting of two or morepolyolefins, microporous membranes or films, fibers, porous fibers,hollow fibers, or microporous fibers which are comprised of a polyolefinin combination with or blended with one or more block copolymers orimpact copolymers as a means of improving the composition,characteristics, performance, and/or properties of the membranes,fibers, porous fibers, materials, layers or textiles made from suchmembranes, fibers or porous fibers, for example, improving thecharacteristics, performance, and/or properties such as hand, drape,quietness, and/or surface coefficient of friction of the membranes,fibers, materials, layers or textiles such as microporous polyolefinmembranes and/or polyolefin fibers in or for textiles or textile end useapplications.

In accordance with selected embodiments or examples, the instantapplication relates to new or improved microporous membranes, new orimproved porous membrane wipes, new or improved microporous membranewipes, and/or methods of manufacture, marketing, and/or use thereof. Theinstant invention is directed toward a new or improved method for oilblotting utilizing a microporous membrane wipe, like use in blotting oilfrom one's skin or face, and/or the removal of fingerprint, smudges andthe like from other surfaces like eyeglasses; electronics; cell phones;displays, optical devices, camera lenses, microscope lenses and otherprecision optics, and/or the like. In at least selected embodiments, themicroporous membrane wipes may be microporous membranes made from impactcopolymers of polyethylene and/or polypropylene. In at least selectedother embodiments, the microporous membrane wipes may be a biaxiallyoriented microporous membrane made from impact copolymers ofpolyethylene and/or polypropylene.

In another embodiment, the microporous membrane wipes of the instantinvention may be used for cleaning surfaces of oil, fingerprints,smudges, etc, including, but not limited to, eyeglasses; electronics;cell phones; displays, optical devices, camera lenses, microscope lensesand other precision optics, the like, etc. Some desired features of themicroporous membrane wipes of the instant invention being used assurface cleaners may include, but are not limited to, the following:designed for delicate tasks; low lint; non-abrasive; pleasant to thetouch; absorbs oil without leaving oily residue on the fingers; providesvisual indication of the absorbed oil; and anti-static dispensing. Themicroporous membrane wipes of the instant invention have been found towork extremely well as a lint free technical wipe for optics and othertechnical needs. Fingerprints, smudges, and the like on display screens,eyeglasses, and similar surfaces are largely oil-based. Consequently,the instant microporous membrane wipes may work particularly well aswipes for these surfaces because of their oil absorption properties. Themicroporous membrane wipes may also have the additional benefits ofbeing very soft to the touch and having very high porosity, thusenhancing its absorptive properties. Similar to the applications thatKimwipes® are typically used for, the instant microporous membranewipes, and particularly biaxially stretched impact copolymer membranewipes, could find wide use as clean room wipes, wipes for high precisionoptics, or even in consumer products as disposable eyeglass wipes inlieu of microfiber cleaning cloths.

In one embodiment, the microporous membrane wipes of the instantinvention could be biaxially-oriented Celgard membranes, such as thosedisclosed in US Patent Publication Nos. 20070196638 and 20110223486(each hereby incorporated by reference herein). Such biaxially-orientedmembranes may be preferred as they may perform even better as skin oilblotters than uniaxially-oriented Celgard membranes because biaxialorientation increases the membranes' porosity. Moreover,biaxially-oriented Celgard membranes made from block copolymers ofpolyethylene and polypropylene have the additional advantage ofexceptionally pleasant touch, relative both to Celgard membranes madefrom pure polypropylene and to commercially available skin oil blotters.However, the invention is not so limited to the preferredbiaxially-oriented microporous membrane wipes, and uniaxially-orientedmicroporous membrane wipes may also be used as the micorporous membranewipes of the instant invention.

In one embodiment, the microporous membrane wipe may be made by adry-stretch process and have substantially round shaped pores and aratio of machine direction tensile strength to transverse directiontensile strength in the range of 0.5 to 4.0. The microporous membranewipe may be a thin, pliable, polymeric sheet, foil, or film having aplurality of pores therethrough.

In a possibly preferred embodiment, the polymers used in the instantmicroporous membrane wipes may be impact copolymers (PP with EPR).

In other select embodiments, the instant wipe may include otheringredients. For example, those ingredients may include: fillers (inertparticulates used to reduce the cost of the wipe, but otherwise havingno significant impact on the manufacture of the wipe or its physicalproperties), anti-static agents, anti-blocking agents, anti-oxidants,lubricants (to facilitate manufacture), and the like.

Example 6

A PP based impact copolymer is extruded to form a film. Extruder melttemperature is 249° C. Polymer melt is fed to an extrusion die set at215° C. The polymer melt is cooled by blowing air. The extruded film hasa thickness of 34 μm and birefringence of 0.0116. The extruded precursoris then annealed at 154° C. for 2 minutes. The annealed film is thencold stretched to 30% at room temperature and hot stretched 190% andrelaxed 61% at 140° C. (total machine direction stretch=159%). The MDstretched film has a thickness of 26 μm and porosity of 40%. The MDstretched film is then TD stretched 260% at 150° C. with 50% MD relax,followed by a simultaneous MD and TD stretch of 50% and 216%,respectively, at 150° C.

Example 6 Data

In the following table the results of Example 6 are summarized andcompared to two commercially available dry-stretched films: A) CELGARD®2400 (single ply polypropylene wipe); and B) CELGARD® 2325 (tri-layerpolypropylene/polyethylene/polypropylene).

TABLE 5 Example 6 TD MD Tensile Tensile MD/TD TD Thickness strengthstrength tensile stretching (um) Porosity (kg/cm²) (kg/cm²) ratio A N/A25.4 37% 160 1700 10.6 B N/A 25.1 40% 146 1925 13.2 Ex 6 450% 17 73% 287558 1.9

With respect to at least certain embodiments directed to batteryseparators, there may be a need for further strengthen or enhance atleast certain battery separators, particularly as the materials becomethinner. One way to obtain materials in the 1-10 μm range is throughtransverse direction (TD) stretching. Biaxial stretching can providetransverse strength that may be lost with uniaxial stretching.

As battery separator materials are stretched in a biaxial manner, newmaterials may be used for further beneficial effect. Use of impactcopolymer materials can be quite effective either alone or incombination with other isotactic polypropylene materials. In the case ofblended polymers, using 1-80% impact copolymer, more preferably 5-30%impact copolymer may be beneficial as the copolymer material leads toeven greater tensile strength and elongation with respect to a porousstretched material, and may provide a greater process window.

Separators made this way can be made in a laminated trilayer fashion,coextruded fashion, or monolayer fashion. These materials may bepreferentially made to be coated with some sort of polymer or ceramiccoating before use in a battery.

Many other modifications and/or variations of the present invention arepossible to the skilled practitioner in the field in light of theteachings herein. It is therefore understood that other embodiments orexamples are contemplated and that, within the scope of the claims, thepresent invention can be practiced other than as herein specificallydescribed.

What is claimed is:
 1. A microporous polyolefin membrane comprises atleast one polyolefin combined with at least one block or impactcopolymer for improving membrane characteristics or performanceproperties, the characteristics or performance properties including atleast one of hand, drape, quietness, and surface coefficient of frictionof the microporous membrane in textile products, wherein the polyolefinincluding polypropylene, polyethylene, poly 1-butene, poly-4-methyl-1pentene, polyhexene, polyoctene, and/or blends, mixtures, orcombinations thereof, and wherein the block or impact copolymercomprises two or more polyolefins in mole fractions in a range ofbetween 1% and 50%.
 2. The microporous membrane according to claim 1wherein the microporous membrane has a thickness of about 12-25 μm andis made with a uniaxial stretch.
 3. The microporous membrane accordingto claim 1 wherein the microporous membrane has a thickness of about5-50 μm and is made with a biaxial stretch, the biaxial stretchincluding a machine direction stretch and a transverse directionstretch, the transverse direction stretch including a simultaneousmachine direction relax.
 4. The microporous membrane according to claim1 wherein the microporous membrane has a thickness of about 5-50 μm andis made with a biaxial stretch, the biaxial stretch including a machinedirection stretch and a transverse direction stretch, without asimultaneous machine direction relax.
 5. The microporous membraneaccording to claim 1 wherein the polyolefin being polypropylene and/orpolyethylene.
 6. The microporous membrane according to claim 1 whereinthe block or impact copolymer comprises polypropylene and polyethylenein a mole fractions in a range of between 1% and 50%.
 7. The microporousmembrane according to claim 1 wherein the microporous membrane has athickness of about 5-50 μm and is made with a uniaxial stretch.
 8. Themicroporous membrane according to claim 1 wherein the microporousmembrane has a thickness of about 5-50 μm and is made with a biaxialstretch, the biaxial stretch including a machine direction stretch and atransverse direction stretch, the transverse direction stretch includinga simultaneous machine direction relax.
 9. The microporous membraneaccording to claim 1 wherein the microporous membrane has a thickness ofabout 5-50 μm and is made with a biaxial stretch, the biaxial stretchincluding a machine direction stretch and a transverse directionstretch, without a simultaneous machine direction relax.
 10. Themicroporous membrane according to claim 1 wherein the block or impactcopolymer being polypropylene and polyethylene and the polypropyleneand/or polyethylene being present at mole fraction between 3% and 10% inthe impact copolymer.
 11. The microporous membrane according to claim 1wherein the block or impact copolymer is extruded using a blown filmmethod or a casted film method to form a nonporous precursor film thatis stretched to form the microporous membrane.
 12. The microporousmembrane according to claim 1 wherein the block or impact copolymercomprises two or more polyolefins selected from the group ofpolypropylene, polyethylene, poly 1-butene, poly-4-methyl-1 pentene,polyhexene, polyoctene and/or blends, mixtures, or combinations thereof.13. A textile material, garment, or product made of a microporouspolyolefin membrane, the membrane comprises a block or impact copolymerincluding two or more polyolefins, or a polyolefin in combination withone or more block or impact copolymers including two or more polyolefinsin mole fractions in a range of between 1% and 50%, the membrane havingimproved composition, characteristics, performance and/or properties,the improvements including hand, drape, “quietness” with movement,and/or surface coefficient of friction of the microporous membrane in orfor the textile material, garment, or product.
 14. The microporousmembrane according to claim 13 wherein the microporous membrane has athickness of about 12-25 μm and is made with a uniaxial stretch.
 15. Themicroporous membrane according to claim 13 wherein the microporousmembrane has a thickness of about 5-50 μm and is made with a biaxialstretch, the biaxial stretch including a machine direction stretch and atransverse direction stretch, the transverse direction stretch includinga simultaneous machine direction relax.
 16. The microporous membraneaccording to claim 13 wherein the microporous membrane has a thicknessof about 5-50 μm and is made with a biaxial stretch, the biaxial stretchincluding a machine direction stretch and a transverse directionstretch, without a simultaneous machine direction relax.
 17. Themicroporous membrane according to claim 13 wherein the block or impactcopolymer being polypropylene and polyethylene and the polypropyleneand/or polyethylene being present at mole fraction between 3% and 10% inthe impact copolymer.
 18. The microporous membrane according to claim 13wherein the block or impact copolymer is extruded using a blown filmmethod or a casted film method to form a nonporous precursor film thatis stretched to form the microporous membrane.
 19. The microporousmembrane according to claim 13 wherein the block or impact copolymercomprises two or more polyolefins selected from the group ofpolypropylene, polyethylene, poly 1-butene, poly-4-methyl-1 pentene,polyhexene, polyoctene and/or blends, mixtures, or combinations thereof.